git config --global user.name "你的名字"
git config --global user.email "你的邮箱"
git clone ${git地址}
cd demo
touch README.md
git add README.md
git commit -m "add README"
git push -u origin master
cd existing_folder
git init
git remote add origin ${git地址}
git add .
git commit
git push -u origin master